The failure rate of crankpin bearing bush of diesel engine under complex working conditions such as high temperature,dynamic load and variable speed is high.After serious wear,it is easy to deteriorate the stress stat...The failure rate of crankpin bearing bush of diesel engine under complex working conditions such as high temperature,dynamic load and variable speed is high.After serious wear,it is easy to deteriorate the stress state of connecting rod body and connecting rod bolt,resulting in serious accidents such as connecting rod fracture and body damage.Based on the mixed lubrication characteristics of connecting rod big endbearing shell of diesel engine under high explosion pressure impact load,an improved mixed lubrication mechanism model is established,which considers the influence of viscoelastic micro deformation of bearing bush material,integrates the full film lubrication model and dry friction model,couples dynamic equation of connecting rod.Then the actual lubrication state of big end bearing shell is simulated numerically.Further,the correctness of the theoretical research results is verified by fault simulation experiments.The results show that the high-frequency impact signal with fixed angle domain characteristics will be generated after the serious wear of bearing bush and the deterioration of lubrication state.The fault feature capture and alarm can be realized through the condition monitoring system,which can be applied to the fault monitoring of connecting rod bearing bush of diesel engine in the future.展开更多
Misalignment is one of the most common causes of wear in bush bearings.Design improvements have been proposed by many researchers.Unfortunately,it did not efficiently reduce the misalignment.Classic geometrical design...Misalignment is one of the most common causes of wear in bush bearings.Design improvements have been proposed by many researchers.Unfortunately,it did not efficiently reduce the misalignment.Classic geometrical designs sometimes reach their limits.For this reason,a bio-inspired design is proposed to solve the impediment.In this article,a bio-inspired bearing suited to misalignment was tested and compared to a classical bush bearing.The contact pressures of both bearings were compared with static Finite Element(FE)simulations for off-center load.Due to the complex shape of the involved contact,the performances of both bearings were also studied over time.Their wear behaviors were predicted with a numerical method.The methodologies emplaced to simulate the wear were described in this paper.Particularly,the wear coefficient determination obtained by experimental testing was detailed.The pressure value,the contact zone and the wear depth were compared and discussed.The wear results for the classical bearing are in accordance with the literature.The simulations show a deeper wear on the classical bush bearing than on the bio-inspired bearing.This leads to a longer period of service life for the bio-inspired bearing.展开更多
基金Supported by the National Natural Science Foundation of China(No.52101343)the Aeronautical Science Foundation(No.201834S9002).
文摘The failure rate of crankpin bearing bush of diesel engine under complex working conditions such as high temperature,dynamic load and variable speed is high.After serious wear,it is easy to deteriorate the stress state of connecting rod body and connecting rod bolt,resulting in serious accidents such as connecting rod fracture and body damage.Based on the mixed lubrication characteristics of connecting rod big endbearing shell of diesel engine under high explosion pressure impact load,an improved mixed lubrication mechanism model is established,which considers the influence of viscoelastic micro deformation of bearing bush material,integrates the full film lubrication model and dry friction model,couples dynamic equation of connecting rod.Then the actual lubrication state of big end bearing shell is simulated numerically.Further,the correctness of the theoretical research results is verified by fault simulation experiments.The results show that the high-frequency impact signal with fixed angle domain characteristics will be generated after the serious wear of bearing bush and the deterioration of lubrication state.The fault feature capture and alarm can be realized through the condition monitoring system,which can be applied to the fault monitoring of connecting rod bearing bush of diesel engine in the future.
基金supported by Airbus Helicopters and Aix-Marseille UniversityThe experimental devices were founded by:European Community,French Ministry of Research and Education and Aix-Marseille Con-urbation Community.
文摘Misalignment is one of the most common causes of wear in bush bearings.Design improvements have been proposed by many researchers.Unfortunately,it did not efficiently reduce the misalignment.Classic geometrical designs sometimes reach their limits.For this reason,a bio-inspired design is proposed to solve the impediment.In this article,a bio-inspired bearing suited to misalignment was tested and compared to a classical bush bearing.The contact pressures of both bearings were compared with static Finite Element(FE)simulations for off-center load.Due to the complex shape of the involved contact,the performances of both bearings were also studied over time.Their wear behaviors were predicted with a numerical method.The methodologies emplaced to simulate the wear were described in this paper.Particularly,the wear coefficient determination obtained by experimental testing was detailed.The pressure value,the contact zone and the wear depth were compared and discussed.The wear results for the classical bearing are in accordance with the literature.The simulations show a deeper wear on the classical bush bearing than on the bio-inspired bearing.This leads to a longer period of service life for the bio-inspired bearing.
